PROJECT SUMMARY/ABSTRACT The proposed K23 Career Development program will provide Dr. Ekaterina Pivovarova with the training and pilot data necessary to conduct independent research in applying implementation science to increase access to empirically based substance use disorder (SUD) treatments for justice involved individuals. Opioid-related drug overdose is a leading cause of death for individuals with justice involvement. Yet, most individuals in the justice system fail to receive the gold standard treatment for opioid use disorder ? medications for opioid use disorder (MOUDs). Drug treatment courts (DTC) are diversionary programs that leverage legal sanctions in exchange for mandatory and court-monitored engagement in SUD treatment. There are over 3,100 DTC programs nationwide that manage thousands of offenders in the community with SUDs. Despite their focus on addiction treatment, DTCs have been slow to incorporate MOUDs as standard practice. Systemic barriers to use of MOUD in DTCs have been well documented and include poor communication and lack of collaboration and relationships with MOUD providers in the community. The proposed study directly addresses barriers in communication and referral practices between DTC and community MOUD providers by adapting an implementation strategy, which has been previously shown as effective in community corrections programs. The Medication for Opioid Use Disorders Implementation ? in Drug Treatment Courts (MOUDI-DTC) is an implementation strategy that aims to improve interagency relationships and increase access to MOUDs for high-risk individuals. Using the Consolidated Framework for Implementation Research (CFIR), a mixed-methods study will be conducted to achieve these specific aims: 1) evaluate current MOUD referral practices, barriers, facilitators, and readiness for change 2) develop MOUDI-DTC implementation strategy and manual, 3) implement MOUDI-DTC for 12 months in three DTCs and evaluate efficacy, acceptance and feasibility of the implementation strategy. The findings will provide preliminary data about efficacy of MOUDI-DTC on increasing referrals and acceptability and feasibility of MOUDI-DTCs to ultimate expand and evaluate the strategy nationwide. The findings will also provide pilot data for developing an R01 randomized clinical trial to compare MOUDI-DTC to referral practices as usual in DTCs. More broadly, this research will lead to development of best-practice guidelines about how DTCs should work with MOUD community providers to increase access to care and referrals to MOUDs. Completing this study will serve as one component of a rigorous training plan for Dr. Pivovarova to receive directed training in 1) implementation science, 2) MOUD, and 3) organizational theory and systems level intervention. During the K23, Dr. Pivovarova will receive individualized and team mentorship from leading researchers in the field of implementation science and SUD treatment in justice settings: Drs. Peter Friedmann (primary), Stephenie Lemon, David Smelson, and Faye Taxman.